The present invention concerns a multi-section header with several frame sections that are joined with each other for articulation and each form a partial working width of the header, wherein outer lateral frame sections are connected with a central frame section with each other by means of a relief element that is adjustable between a springy setting and a locked setting.
A header of the aforementioned kind is disclosed in U.S. Pat. No. 6,675,568. The header disclosed therein comprises a central frame section and two outer lateral frame sections joined for articulation thereto. Since the ground of a field across the total working width of the header does not remain flat upon forward travel of the harvester to which the header is attached in use, but can exhibit elevations and depressions, the individual frame sections with their partial working widths are supposed to better adapt to the soil contour by means of their articulated connection with each other. In particular the lateral frame sections with their free ends can pivot up or down relative to the central frame section in order to adapt in this way to a ground contour that is ascending or descending in lateral direction relative to the transverse axis of the central frame section.
In order to increase the reaction time of the lateral frame sections and to facilitate adaptation to the ground without risking in this context damaging the lateral frame sections, the lateral frame sections are connected with the central frame section by a relief element, respectively. The relief element supports a portion of the weight of the lateral frame section and introduces it into the frame of the central frame section. The remaining pressure with which a lateral frame section is supported on the ground is thus significantly reduced. By designing the relief element as a spring, the lateral frame sections can swing up or down with their free ends against the spring force when a ground contour changes during harvesting.
However, free swinging of the lateral frame sections against the spring in the relief element is not desirable in all situations of use of the header. In the header known from the prior art, the springs in the relief elements can therefore be bypassed by a selectively insertable rigid lock. With this lock, the relief elements can thus only be operated either with free spring action or in a rigid configuration.
It is the object of the present invention to provide an adjusting possibility that provides a greater variety in regard to the adjustment of the spring behavior of the relief element and that is easily operable.